title: Aetiology of molar-incisor hypomineralisation (MIH) in Brazilian children.
abstract: OBJECTIVE
  To determine the potential aetiological factors related to molar-incisor hypomineralisation (MIH) in Brazilian children.
  
  
  METHODS
  A total of 1,151 children aged 7-12 years (mean 8.86 ± 1.28), born and living in the urban area of Araraquara, Brazil, were examined by two examiners evaluating the presence of MIH according to criteria suggested by the European Academy of Paediatric Dentistry (2003). Their mothers completed a structured questionnaire about medical history, from pregnancy to the first 3 years of the children's life. Descriptive analyses of data and odds ratios (OR) with 95 % test-based confidence intervals (CI) were estimated. Chi-square test was used to evaluate the differences between groups.
  
  
  RESULTS
  The prevalence of MIH in the children was 12.3 %. The interviewing response rate was 90.4 %. The prevalence of miscarriage history (25 vs. 15.4 %; OR = 1.21; 95 % CI 0.30-4.92) and occurrence of anaemia (23 vs. 12.4 %; OR = 2.07; 95 % CI 0.50-8.63) were higher in mothers from MIH group than those from non-MIH group. However, these associations were not statically significant. In the children's medical history, rhinitis, bronchitis (56.5 vs. 52.5 %; OR = 1.17; 95 % CI 0.82-1.68), and high fever (20.4 vs. 18.2 %; OR = 1.14; 0.73-1.76) were more prevalent in MIH group, but there were no significant differences between the groups (p > 0.05).
  
  
  CONCLUSIONS
  No possible aetiological factor investigated was associated with MIH. Prospective studies are needed to define the aetiological factors involved with MIH.
authors.affiliation: Department of Paediatric Dentistry and Orthodontics, Araraquara Dental School; Univ Estadual Paulista (UNESP), Rua Humaitá, 1680, Araraquara, SP, 14801-903, Brazil.
authors.forename: J F
authors.initials: JF
authors.lastname: Souza
authors.forename: F
authors.initials: F
authors.lastname: Jeremias
authors.forename: C M
authors.initials: CM
authors.lastname: Costa-Silva
authors.forename: L
authors.initials: L
authors.lastname: Santos-Pinto
authors.forename: A C C
authors.initials: AC
authors.lastname: Zuanon
authors.forename: R C L
authors.initials: RC
authors.lastname: Cordeiro